Backrest adjusting mechanism and a seat with the same

ABSTRACT

The backrest adjusting mechanism comprises a base, a cushion, a supporting frame, a backrest, an air pressure rod, a connecting rod and a steel wire core; the cushion is fixed to a top of the adjusting base; the supporting frame is rotationally connected to a rear end of the adjusting base; the backrest is fixed on the supporting frame; the air pressure rod is rotationally connected with the supporting frame; the rear end of the base is provided with a fixing frame; the connecting rod is rotationally connected with the fixing frame and a movable rod; the connecting rod and the fixing frame are provided with a limiting block; when the backrest is used, two of the limiting block are propped against each other to fix the backrest at a specific position.

FIELD OF THE INVENTION

The present invention relates to the technical field of electricvehicles, particularly, relates to a backrest adjusting mechanism and aseat with the same.

BACKGROUND OF THE INVENTION

The vehicle is an indispensable mean of transportation in daily life.Particularly, automobiles and motorcycles almost become a part of thelife of modern people. However, because fuel motor vehicles such asmotorcycles or automobiles generally have the problem of air pollution.Under the trend of pursuing environmental protection as much as possibleat present, very environmental friendly electric scooters are generatedcorrespondingly.

For convenient storage and transportation in daily life, the seats inthe existing electric scooters mostly adopt foldable design, butbackrests of the seats can only be fixed at a position forming aspecific angle with a cushion when being pulled up. And for differentusers, the needs on angles between the backrests and the cushion aredifferent, so that inconvenience is caused.

And, in the prior art, in using, for meet the different needs, the anglebetween the cushion and the backrest in a seat can be adjustedappropriately. However, when adjusting the angle between the cushion andthe backrest, the back rest moves too fast, accompanied by impact,vibration and other problems, which will seriously affect the use ofusers and shorten the service life of the seat.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a backrest adjustingmechanism, solving the problems that the backrest of the seat of theexisting electric scooter can only be fixed at a position forming aspecific angle with a cushion when being pulled up, and for differentusers, the needs on the angle between the backrest and the cushion aredifferent, so that inconvenience is caused.

The second object of the present invention is to solve the problems thatwhen adjusting the angle between the cushion and the backrest, thebackrest moves too fast, accompanied by impact, vibration and otherproblems, which will seriously affect the use of users and shorten theservice life of the seat.

The backrest adjusting mechanism includes an adjusting base, a cushion,a supporting frame, a backrest, an air pressure rod, a connecting rodand a steel wire core.

The cushion is fixed to a top of the adjusting base; the supportingframe is rotationally connected to a rear end of the base; the backrestis fixed on the supporting frame; the air pressure rod is rotationallyconnected with the supporting frame; the rear end of the adjusting baseis provided with a fixing frame; one end of the connecting rod isrotationally connected on the fixing frame, the other end saidconnecting rod is rotationally connected with a movable rod in the airpressure rod; both of the connecting rod and the fixing frame areprovided with a limiting block; when the backrest is used, two of thelimiting blocks are propped against each other to fix the backrest at aspecific position; one side of the base is actively connected with abuckle plate; one end of the steel wire core is fixed on a valve coreswitch of the air pressure rod, the other end of the steel wire core isfixed on the buckle plate.

Preferably, the air pressure rod can drive an included angle between thebackrest and the adjusting base to be changed in a range of 100°˜120°.

Preferably, a bottom of the adjusting base is provided with a protectivetube, one end of the protective tube is fixed on the adjusting base, andthe other end of the protective tube is fixed on the movable rod of theair pressure rod; the steel wire core is received in the protectivetube.

Preferably, one side of the adjusting base is fixed with two lowersupporting lugs; two ends of the buckle plate are actively connected onthe two lower supporting lugs.

Preferably, a rear end of the supporting frame is fixed with two uppersupporting lugs; the air pressure rod is rotationally connected on thetwo upper supporting lugs.

Preferably, two ends of the steel wire core are respectively providedwith a clamping block; the buckle plate and the valve core switch of theair pressure rod are respectively provided with a clamping groovecorresponding to the clamping block; the clamping block is clamped inthe clamping groove.

Preferably, the bottom of the adjusting base is provided with aplurality of mounting holes and a plurality of mounting grooves.

The technical effect of the backrest, adjusting mechanism in the presentinvention is as follows:

The supporting frame is rotationally connected with the adjusting baseso that the backrest and the cushion can be folded, and when the cushionis pulled up, the backrest is fixed on a position with an included angleof 100° with the cushion by two limiting blocks, then the buckle plateis controlled to drive the steel wire core to trigger the valve coreswitch of the air pressure rod, so that the backrest and the cushion canbe fixed at any included angle between 100°˜120°, so as to meet theneeds of different people.

A seat with an adjustable backrest includes a cushion and a backrest,the backrest is rotationally connected on one side of the cushion, abottom of the cushion is provided with an adjusting base, the adjustingbase is provided with a backrest adjusting mechanism for adjusting therotating angle of the backrest backwards; the angle adjusting mechanismcomprises an adjusting handle, limiting sliding block, an air pressurerod and a steel inhaul cable.

The adjusting base comprises an, adjusting plate installed at the bottomof the cushion, and a supporting plate extending upwards along one sideof the adjusting plate.

One end of the adjusting handle is rotationally connected with theadjusting plate, and the other end is a free end extends out of thecushion, forming, a handle for a user to apply force.

The limiting sliding block is sliding connection with the supportingplate, one side, close to the adjusting plate, of the limiting slidingblock is fixed with a rotating shaft, the other side, far away from theadjusting plate, is propped against the bottom of the backrest.

The cylinder body of the air pressure rod is rotationally connected withthe rotating shaft; a movable rod of the air pressure rod is fixed onthe adjusting plate; and the movable rod is provided with a valve coreswitch, which is used to control the opening or closing of the airpressure rod.

The steel inhaul cable is actively connected with the adjusting plate,one end of the steel inhaul cable is fixed with the valve core switch,the other end of the the steel inhaul cable is fixed with the adjustinghandle.

When using, pulling the adjusting handle outwards for pulling the steelinhaul cable to open the valve core switch, so that the movable rod ofthe air pressure rod can do telescopic movement, and push the limitingsliding block to move upwards and downwards along the supporting plate.

Preferably, the rotating angle that the backrest can be rotated is in arange of 0°˜120°.

Preferably, the steal inhaul cable includes a protective tube and asteel wire core; the protective tube is sleeved on an outer surface ofthe steel wire core, the steel wire core is received in the protectivetube and can slid in it.

Preferably, the limiting sliding block is provided with sliding columns,the supporting plate is provided with sliding grooves corresponding tothe positions of the sliding columns; the sliding columns extend intothe sliding grooves and are sliding connection with the sliding groove.

Preferably, each of the sliding grooves is provided with an elasticbuffer piece, one end of which is fixed in the sliding groove, the otherend is propped against one side of the limiting sliding block close tothe cushion.

The technical, effect of the backrest adjusting mechanism in the presentinvention is as follows:

The present invention uses the air pressure rod to drive the limitingsliding block to move, the limiting sliding block can randomly adjustthe moving distance in a stroke range of the movable rod of the airpressure rod, it is easier to meet the needs of the users. The userreleases the adjusting handle at any position in the stroke range of themovable rod of the air pressure rod, the valve core switch is closed,the movable rod is fixed at a certain position, finishing adjustment ofthe backrest. In the process of the air pressure rod being pushed, themoving speed of the air pressure rod is stable, and combining that theelastic buffer piece, which can realize shock absorption to the limitingsliding block, which can avoid the adjustment speed of the backrest toofast, and accompanied with impact, vibration and other problems.

A seat with an adjustable backrest includes a cushion and a backrest,the backrest is rotationally connected on one side of the cushion, abottom of the cushion is equipped with an adjusting base, the adjustingbase is provided with a backrest adjusting mechanism for adjusting therotating angle of the backrest.

Preferably, the rotating angle adjusting mechanism comprises anadjusting handle, a limiting sliding block and a torsion spring.

The adjusting base comprises an adjusting plate installed at the bottomof the cushion, and a supporting plate extending upwards along one sideof the adjusting plate, the adjusting, plate is provided with a clampingpart.

The limiting sliding block is sliding connection with the supportingplate, one side, close to the adjusting plate, of the limiting slidingblock is fixed with a rotating shaft, one side, far away from theadjusting plate, is propped against the bottom of the backrest.

One end of the adjusting handle is fixed with a gear adjusting block,the other end of the adjusting handle extends out of the adjusting base,forming a handle for pulling; the gear adjusting block is provided witha clamping block actively connected with the clamping part, and aconnecting part is rotationally connected with the rotating shaft;

The torsion spring is sleeved on the rotating shaft, two ends thereofare respectively extended with a torsion arm, one end of the torsionarms is fixedly connected with the gear adjusting block, the other endof the torsion arms is fixed with the limiting sliding block.

Preferably, the rotating angle that the backrest can be rotated is in arange of 0°˜130°.

Preferably, the clamping part is composed of three clamping groovesarranged in turn from left to right, when assembling, the clamping blockis just located in any one of the three clamping grooves.

Preferably, a bump is arranged between the two adjacent clampinggrooves, the left side of the bump is provided with a circular arc partconnected with s top of the right side wall of the clamping groove.

Preferably, the limiting sliding block is provided with sliding columns,the supporting plate is provided with sliding grooves corresponding tothe positions of the sliding columns; the sliding columns extend intothe sliding grooves, and is sliding connection with the sliding grooves.

Preferably, each of the sliding grooves is provided with an elasticbuffer piece, one end of the elastic buffer piece is fixed with thesliding groove, the other end of the elastic buffer piece is fixed withone side of the limiting sliding block close to the adjusting plate.

Preferably, the bump is located in the right one of the three clampinggrooves, the backrest can rotate towards the right at a angle 10°.

Preferably, the bump is located in the left one of the three clampinggrooves, the backrest can rotate towards the right at a angle 30°.

The technical effect of the backrest adjusting mechanism in the presentinvention is as follows:

1. the backrest can be rotated to be folded on the cushion, when theuser is not used, it is convenient to storage. When the user uses theseat, the user only needs to rotate the backrest from the cushion, whichcan improve the comfort of the seat.

2. Using the adjusting handle to twist the torsional spring so as tostoring and releasing angle energy by the torsion spring or through theshaft rotating force arm around the torsional spring to statically fixthe bump and the clamping grooves on the gear adjusting block, ensuringthe stability of the gear adjusting block, so that the limiting slidingblock is not easy to loose.

3. The limiting sliding block is connected in the sliding grooves of thesupporting plate through the sliding columns; the present invention isprovided with an elastic buffer piece in each of the sliding groove tobuffer the impact force between the backrest and the limiting slidingblock.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the backrest adjusting mechanismaccording to an embodiment in the present invention in a using state;

FIG. 2 is an enlarged view of A in FIG. 1;

FIG. 3 is a local decomposition view of the backrest adjusting mechanismaccording to the present invention;

FIG. 4 is a perspective view of the backrest adjusting mechanismaccording to the present invention in a folded state;

FIG. 5 is a perspective view of the backrest adjusting mechanismaccording to the other embodiment in the present invention;

FIG. 6 is a perspective view of the backrest adjusting mechanism shownin FIG. 5 in other view angle;

FIG. 7 is a decomposition view of the backrest adjusting mechanism shownin FIG. 5;

FIG. 8 is a perspective view of the backrest adjusting mechanismaccording to another embodiment in the present invention;

FIG. 9 is a perspective view of the backrest and cushion folded in thebackrest adjusting mechanism shown in FIG. 8;

FIG. 10 is the other perspective view of the backrest adjustingmechanism shown in FIG. 8 in the other view angle;

FIG. 11 is a decomposition view of the backrest adjusting mechanismremoved the cushion shown in FIG. 8;

FIG. 12 is another perspective view of the backrest adjusting mechanismshown in FIG. 8 in the other view angle;

FIG. 13 is an enlarged view of A in FIG. 12.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

In order to make the purpose of the present invention, technicalsolution and advantages are more clearly understood, with reference tothe accompanying drawings and examples, the present invention is furtherexplained in detail. It should be understood that the specificembodiment described herein is only for explaining the presentinvention, and not for defining the present invention.

It should be noted that, when the element is referred to as “fixed to”or “set on” another element, it can be directly on the other element ormay exist in the middle element at the same time; When one element isreferred to as “connected to” another element, it may be directlyconnected to another element or may be present at the same time as thecentering element.

Embodiment One

Referring to FIG. 1 to FIG. 4, a backrest adjusting mechanism includes abase 10, a cushion 1, a supporting frame 3, a backrest 2, an airpressure rod 20, a connecting rod 4 and a steel wire core 54.

The cushion 1 is fixed to a top of the base 10; the supporting frame 3is rotationally connected to a rear end of the adjusting 10; thebackrest 2 is fixed on the supporting frame 3; the air pressure rod 20is rotationally connected with the supporting frame 3; the rear end ofthe adjusting base 10 is provided with a fixing frame 6; one end of theconnecting rod 4 is rotationally connected on the fixing frame 6 theother end of the connecting rod 4 is rotationally connected with amovable rod 21 in the air pressure rod 20; both of the connecting rod 4and the fixing frame 6 are provided with a limiting block 7; when thebackrest 2 is used, two of the limiting blocks 7 are propped againsteach other to fix the backrest 2 at a specific position; one side of theadjusting base 10 is actively connected with a buckle plate 30; one endof the steel wire core 54 is fixed on a valve core switch 22 of the airpressure rod 20, the other end of the steel wire core 54 is fixed on thebuckle plate 30.

In a preferably technical scheme in the present invention, the airpressure rod 20 can drive the rotating angle between the backrest 2 andthe adjusting base 10 to be changed in a range of 100°˜120°.

In a preferably technical scheme in the present invention, the steelwire core 54 is in a protective tube 51 used for avoiding the damage ofthe steel wire core 54.

In a preferably technical scheme in the present invention, one side ofthe adjusting base 10 is fixed with with two lower supporting lugs 8;two ends of the buckle plate 30 are actively connected on the two lowersupporting lugs 8.

In a preferably technical scheme in the present invention, the back endof the supporting frame 3 is fixed with two upper supporting lugs 9; theair pressure rod 20 is rotationally connected on the two uppersupporting lugs 9.

In a preferably technical scheme in the present invention, two ends ofthe steel wire core 54 are respectively provided with a clamping block52; the buckle plate 30 and the valve core switch 22 of the air pressurerod 20 are provided with a clamping groove 53 corresponding to theclamping block 52; the clamping block 52 is clamped in the clampinggroove 53.

In a preferably technical scheme in the present invention, the bottom ofthe adjusting base 10 is provided with a plurality of mounting holes 18and mounting grooves 19.

The working process of the present invention is as follows:

when using the electric vehicle, the backrest 2 on the seat is pulledup, the limiting block ‘7’ of the fixing frame 6 and the limiting block7 of the connecting rod 4 are propped against each other, at this time,the included angle α between the backrest 2 and the cushion 1 is 100°,then by pulling the buckle plate 30 to drive the steel inhaul cable 50to trigger the valve core switch 22 of the air pressure rod 20. The airpressure rod 20 generates a force to push the backrest 2, while the userapplies force to the back rest 2 through the user's back or hand to pushthe movable rod 21 of the the air pressure rod 20 inwards, so as tocontrol the included angle α between the backrest 2 and the cushion 1 atany suitable angle. Loosening the buckle plate 30 to make the steel wirecore 54 recovery, so that the valve core switch 22 of the air pressurerod 20 is closed, the backrest 2 and the cushion 1 is fixed at acorresponding position.

Embodiment 2

Please referring to FIG. 5-7, a backrest adjusting mechanism includes acushion 1 and a backrest 2, the backrest 2 is rotationally connected onone side of the cushion 1, a bottom of the cushion 1 is provided with anadjusting base 10, the adjusting base 10 is provided with a backrestadjusting mechanism 40 for adjusting the rotating angle of the backrest2 backwards; the backrest adjusting mechanism 40 comprises an adjustinghandle 41, a limiting sliding block 42, an air pressure rod 20 and asteel inhaul cable 50.

The adjusting base 10 comprises an adjusting plate 11 installed at thebottom of the cushion 1, and a supporting plate 12 extending upwardsalong one side of the adjusting plate 11.

One end of the adjusting handle 41 is rotationally connected with theadjusting plate 11, the other end of the adjusting handle 41 extends outof the cushion 1, forming a handle 45 for the user to apply force.

The limiting sliding block 42 is sliding connection with the supportingplate 12. One side, close to the adjusting plate 11, of the limitingsliding block 42 42 is fixed with a rotating shaft 44, one side, faraway from the adjusting plate 11, is propped against the bottom of thebackrest 2.

The cylinder body of the air pressure rod 20 is rotationally connectedwith the rotating shaft 44; the movable rod 21 of the air pressure rod20 is fixed on the adjusting plate 11; and the air pressure rod 20 isprovided with a valve core switch 22, which is used to control theopening or closing of the air pressure rod 20. When the valve coreswitch 22 is opening, the movable rod 21 of the air pressure rod 20 cando telescopic movement. When the valve core switch 22 is closed, themovable rod 21 of the air pressure rod 20 is fixed, it can not dotelescopic movement any more.

The steel inhaul cable 50 is actively connected on the adjusting plate11, one end of the steel inhaul cable 50 is fixed with the valve coreswitch 22 the other end of the the steel inhaul cable 50 is fixed withthe adjusting handle.

When using, pulling the adjusting handle 11 outwards, for pulling thesteel inhaul cable 50 to open the valve core switch 22, so that themovable rod 21 of the air pressure rod 20 can do telescopic movement,and push the limiting sliding block 42 to move upwards and downwardsalong the supporting plate 12.

Preferably, the rotating angle that the backrest 2 can be rotated is ina range of 0°˜120°.

Preferably, the steal inhaul cable 50 includes a protective tube 51, asteel wire core 54, the protective tube 51 is sleeved on the outersurface of the steel wire core 54, the steel wire core 54 is slidingconnection in the protective tube 51.

Preferably, the limiting sliding block 42 is provided with slidingcolumns 421, the supporting plate 12 is provided with sliding grooves121 corresponding to the positions of the sliding columns 421; thesliding columns 421 extend into the sliding grooves 121, and are slidingconnection with the sliding groove 121.

Preferably, each of the sliding grooves 121 is provided with an elasticbuffer piece 123, one end of which is fixed with the sliding groove 121,the other end is propped against one side of the limiting sliding block42 close to the cushion 1.

The working principle of the present invention is as follows:

when the backrest 2 and the cushion 1 is in a folded state, the includedangle α is equal to 0, at this time, the backrest 2 and the limitingsliding block 42 are separated.

When the backrest 2 is opened, the included angle α is equal to 100°, atthis time, the bottom of the backrest 2 and the top part of the limitingsliding block 42 is propped against for limiting the backrest 2 torotate backwards.

When the user adjusts the backrest 2, only needs to pull the adjustinghandle 41, the adjusting handle 41 pulls the steel inhaul cable 50, theother end of which pulls the valve core switch 22 of the air pressurerod 20, so that the movable rod 21 of the air pressure rod 20 can dotelescopic movement.

At this time, the user controls the backrest 2 to be folded forwards orbe rotated backwards by his hand or his back, such as the backrest 2 tocontinue to rotate backwards (i.e., the backrest 2 continues to rotatealong the B direction shown in FIG. 5), the backrest 2 can push thelimiting sliding block 42 to move downwards. The movable rod 21 of theair pressure rod 20 can do shrink motion driving the cylinder body ofthe air pressure rod 20 to move, the cylinder body of the air pressurerod 20 drives the limiting sliding block 42 to move downwards until thebackrest 2 rotates to a specified angle, then releases the adjustinghandle 41, then the valve core switch 22 is closed, the movable rod 21of the air pressure rod 20 stops moving for fixing the limiting slidingblock 42 and making it not continuously move. But also because thebackrest 2 and the limiting sliding block 42 are propped against eachother, the backrest 2 can not rotate to the right, so as to finish theadjustment of the backrest 2.

Although it should be noted that when 100°≤α≤120°, the backrest 2 can berandomly adjusted at any of the rotating angle, that, only by pullingthe adjusting handle 41 to drive the steel inhaul cable 50 to open orclose the valve core switch 22 of the air pressure rod 20, can realizethe adjustment of the backrest 2.

In the present invention, using the air pressure rod 20 to drive thelimiting sliding block 42 to move, the limiting sliding block 42 canrandomly be adjusted the moving distance in the stroke range of themovable rod 21 of the air pressure rod 20, it is easier to meet theneeds of the different user. The users release the adjusting handle 41at any position in, the stroke rang of the movable rod 21 of the airpressure rod 20 to close the valve core switch 22, that is to say thelength of the movable rod 21 is fixed at a certain position, finishingthe adjustment of the backrest 2. And in the process of the air pressurerod 20 being pushed, the moving speed of the movable rod 21 is stable,combining that the elastic buffer piece 123 realizes shock absorption tothe limiting sliding block 42, which can avoid the adjustment speed ofthe backrest 2 too fast, and accompanied with impact, vibration andother problems.

Embodiment 3

Referring to FIG. 8-12, the backrest adjustable seat includes a cushion1 and a backrest 2, the backrest 2 is rotationally connected on one sideof the cushion 1, the bottom of the cushion 1 is equipped with anadjusting base 10, the adjusting base 10 is provided with a backrestadjusting mechanism 40 for adjusting the rotating angle of the backrest2 backwards.

Preferably, the backrest adjusting mechanism 40 comprises an adjustinghandle 41, a limiting sliding block 42, and a torsion spring 46.

The adjusting base 10 comprises an adjusting plate 11 installed at thebottom of the cushion 1, and a supporting plate 12 extending upwardsalong one side of the adjusting plate 11, the adjusting plate 11 isprovided with a clamping part 60.

The limiting sliding block 42 is sliding connection with the supportingplate 12, one side, close to the adjusting plate 11, of the limitingsliding block 42 is fixed with a rotating shaft 44, one side, far awayfrom the adjusting plate 11, is propped against the bottom of thebackrest 2.

One end of the adjusting handle 41 is fixed with a gear adjusting block47, the other end of the adjusting handle extends out of the adjustingbase 10 forming a handle 45 for pulling; the gear adjusting block 47 isprovided with a clamping block 471 actively connected with the clampingpart 60 and a connecting part 472 rotationally connected with therotating shaft 44.

The torsion spring 46 is sleeved on the rotating shaft 44, two endsthereof are respectively extended with a torsion arm, one end of thetorsion arm is fixedly connected with the gear adjusting block 47, theother end of the torsion 46 is fixed with the limiting sliding block 42.

Preferably, the rotating angle that the backrest 2 can be rotated in arange of 0°˜130°.

Preferably, the clamping part 60 is, composed of three clamping grooves61 arranged in turn from left to right, when assembling, the clampingblock 471 is just located in any one of the three clamping grooves 61.

Preferably, a bump 62 is arranged between the two adjacent clampinggrooves 61, the left side of the bump 62 is provided with a circular arcpart 63 connected with the top of the right side wall of the clampinggrooves 61. Accordingly, it is convenient for the clamping part 60 tomove, improves the rationality of the structure of clamping grooves, andensures that the clamping part 60 moves more smoothly.

Preferably, the limiting sliding block 42 is provided with slidingcolumns 421, the supporting plate 12 is provided with sliding grooves121 corresponding to the position of the sliding columns 421; thesliding columns 421 extend into the sliding grooves 121, and are slidingconnection with the sliding grooves 121.

Preferably, each of the sliding grooves 121 is provided with an elasticbuffer piece 123, one end of the elastic buffer piece 123 is fixed withthe sliding groove 121, the other end of the elastic buffer piece 123 isfixed with one side of the limiting sliding block 42 close to theadjusting plate 11. When the limiting sliding block 42 is pressed, itslides in the direction of the elastic buffer piece 123 and compressesthe elastic buffer piece 123. The elastic buffer piece 123 plays a rolein buffering the impact force between the backrest 2 and the limitingsliding block 42, thereby prolonging the service life of the seat. Theelastic buffer piece 123 in the present invention is a spring.

Preferably, the clamping block 471 is located in the right one of theclamping grooves 61, the backrest 2 can rotate backwards at a angle 10°.

Preferably, the clamping block 471 is located in the left one of theclamping grooves 61, the backrest 2 can rotate backwards at a angle 30°.

The working principle of the present invention is as follows:

When the backrest 2 and the cushion 1 is in a folded state, the includedangle α is equal to 0, at this time, the backrest 2 and the limitingsliding block 42 are separated.

When the backrest 2 is opened, the included angle α is equal to 100°, atthis time, the bottom of the backrest 2 and the top part of the limitingsliding block 42 is propped against for limiting the backrest 2 torotate backwards.

When the user applies downward force on the handle 45, the connecting,part 472 of the adjusting handle 41 is driven to rotate along therotating shaft 44, thereby driving the clamping part 60 to movedownwards and separating from the clamping grooves 61, so that thelimiting sliding block 42 can move. At this time, the user properlyapplies force to the backrest 2, the backrest 2 rotates backwards andpresses the limiting sliding block 42 downwards, the limiting slidingblock 42 is connected with the gear adjusting block 47 to move from theright to the left. At the time when the backrest 2 rotates to theincluded angle α equal to 120°, the gear adjusting block 47 moves fromthe right clamping grooves 61 to the adjacent middle clamping groove 61.If the user releases the adjusting handle 41, the gear adjusting block47 is clamped in the middle clamping groove 61 and can not move anymore, namely finishing the adjustment of the backrest 2. Of course, whenthe backrest 2 rotates to the included angle α equal to 130°, the gearadjusting block 47 can be clamped into the left clamping groove 61, thebackrest 2 reaches the maximum rotating angle.

The backrest adjustable mechanism with the reasonable structure, solvesthe problem that the backrest 2 of the existing electric scooter canonly be fixed in a seat at a specific angle, for different users, theneeds of the include angle between the backrest 2 and the cushion 1 isdifferent, thus the inconvenience is caused.

The above is only the preferred embodiment of the present invention, thestructure is not limited to the listed shape, any modification in thespirit and principle of the present invention, equivalent replacementand improvement and so on, are contained in the protection range of thepresent invention.

What is claimed:
 1. The backrest adjusting mechanism, wherein comprisingan adjusting base, a cushion, a supporting frame, a backrest, an airpressure rod, a connecting rod and a steel wire core; said cushion isfixed to a top of said base; said supporting frame is rotationallyconnected to a rear end of said base; said backrest is fixed on saidsupporting frame; said air pressure rod is rotationally connected withsaid supporting frame; said rear end of said base is provided with afixing frame; one end of said connecting rod is rotationally connectedon said fixing frame, the other end of said connecting rod isrotationally connected with a movable rod of said air pressure rod; bothof said connecting rod and said fixing frame are provided with alimiting block; when said backrest is used, two of said limiting blockare propped against each other to fix said backrest at a specificposition; one side of said adjusting base is actively connected with abuckle plate; one end of said steel wire core is fixed on a valve coreswitch of said air pressure rod, the other end of said steel wire coreis fixed on said buckle plate.
 2. The backrest adjusting mechanismaccording to claim 1, wherein said air pressure rod can drive anincluded angle between said backrest and said adjusting base to bechanged in a range of 100°˜120°.
 3. The backrest adjusting mechanismaccording to claim 1, wherein a bottom of said adjusting base isprovided with a protective tube, one end of said protective tube isfixed on said adjusting base, the other end of said protective tube isfixed on said movable rod of said air pressure rod; said steel wire coreis received in said protective tube.
 4. The backrest adjusting mechanismaccording to claim 1, wherein one side of said adjusting base is fixedwith with two lower supporting lugs; two ends of said buckle plate areactively connected with said two lower supporting lugs.
 5. The backrestadjusting mechanism according to claim 1, wherein a rear end of saidsupporting frame is fixed with two upper supporting lugs; said airpressure rod is rotationally connected on said two upper supportinglugs.
 6. The backrest adjusting mechanism according to claim 1, whereintwo ends of said steel wire core are respectively provided with aclamping block; said buckle plate and said valve core switch of said airpressure rod are respectively provided with a clamping groovecorresponding to said clamping block; said clamping block is clamped insaid clamping groove.
 7. The backrest adjusting mechanism according toclaim 1, wherein said bottom of said base is provided with a pluralityof mounting holes and a plurality of mounting grooves.
 8. A seat with anadjustable backrest, comprising a cushion and a backrest, said backrestis rotationally connected with one side of said cushion, wherein abottom of said cushion is provided with an adjusting base, saidadjusting base is provided with a backrest adjusting mechanism foradjusting a rotating angle of said backrest; said backrest adjusting,mechanism comprises an adjusting handle, a limiting sliding block, anair pressure rod and a steel inhaul cable; said adjusting base comprisesan adjusting plate installed at said bottom of said cushion, and asupporting plate extending upwards along one side of said adjustingplate; one end of said adjusting handle is rotationally connected onsaid adjusting plate, and the other end is a free end, which extends outof said cushion, forming a handle for a user to apply force; saidlimiting sliding block is sliding connection with said supporting plate,one side, close to said adjusting plate, of said limiting sliding blockis fixed with a rotating shaft, the other side, far away from saidadjusting plate, is propped against said bottom of said backrest; acylinder body of said air pressure rod is rotationally connected withsaid rotating shaft; a movable rod of said air pressure rod is fixed onsaid adjusting plate; and said movable rod is provided with a valve coreswitch, which is used to control opening or closing of said air pressurerod; said steel inhaul cable is actively connected on said adjustingplate, one end of said steel inhaul cable is fixed with said valve coreswitch, the other end of said steel inhaul cable is fixed with saidadjusting handle; in using, pulling said adjusting handle outwards forpulling said steel inhaul cable to open said valve core switch, so thatsaid movable rod of said air pressure rod can do telescopic movement,and push said limiting sliding block to move upwards and downwards alongsaid supporting plate.
 9. The seat with an adjustable backrest accordingto claim 8, wherein said rotating angle that said backrest can berotated is in a range of 0°˜120°.
 10. The seat with an adjustablebackrest according to claim 8, wherein said limiting sliding block isprovided with sliding, columns, said supporting plate is provided withsliding grooves corresponding to said sliding columns; said slidingcolumns extend into said sliding grooves and are sliding connection withsaid sliding grooves.
 11. The seat with an adjustable backrest accordingto claim 10, wherein each of said sliding grooves is provided with anelastic buffer piece, one end of which is fixed with said slidinggroove, the other end is propped against one side of said limitingsliding block close to said cushion.
 12. A seat with an adjustablebackrest includes a cushion and a backrest, said backrest isrotationally connected on one side of said cushion, wherein a bottom ofsaid cushion is equipped with an adjusting base, said adjusting base isprovided with a backrest adjusting mechanism for adjusting a rotatingangle of said backrest; said backrest adjusting mechanism comprises anadjusting handle, a limiting sliding block, and a torsion spring; saidadjusting base comprises an adjusting plate installed at said bottom ofsaid cushion, and a supporting plate extending upwards along one side ofsaid adjusting plate, said adjusting plate is provided with a clampingpart; said limiting sliding block is sliding connection with saidsupporting plate, one side, close to said adjusting plate, of saidlimiting sliding block is fixed with a rotating shaft, the other side,far away from said adjusting plate, is propped against said bottom ofsaid backrest; one end of said adjusting handle is fixed with a gearadjusting block, the other end of said adjusting handle extends out ofsaid adjusting base forming a handle for pulling; said gear adjustingblock is provided with a clamping block actively connected with saidclamping part, and a connecting part rotationally connected on saidrotating shaft; said torsion spring is sleeved on said rotating shaft,two ends thereof are respectively extended with a torsion arm, one ofsaid torsion arms is fixedly connected with said gear adjusting block,the other of said torsion arms is fixed with said limiting slidingblock.
 13. The seat with an adjustable backrest according to claim 12,wherein said rotating angle that said backrest can be rotated is in arange of 0°˜130°.
 14. The seat with an adjustable backrest according toclaim 13, wherein said clamping part is composed of three clampinggrooves arranged in turn from a left to a right, when assembling, saidclamping block is just located in any one of said three clampinggrooves.
 15. The seat with an adjustable backrest according to claim 14,wherein a bump is arranged between two adjacent said clamping grooves, aleft side of said bump is provided with a circular arc part connectedwith a top of a right, side wall of said clamping grooves.